Heterogeneity in Autism: How to Deal with It? a Systematic Review
Objectives: The objectives of this study were to compare the results of various subgrouping methods, and compare the results of establishing subgroups using different (domains of) variables.
Methods: A systematic review was conducted of 108 papers published after 2001 that have subgrouped participants, of which at least some had a diagnosis of ASD. A specific interest of this review was the method that was used to validate subgroups.
Results: Almost all articles validate subgroup results using variables that were measured concurrently, but were not included in the subgrouping procedure. Investigations into stability over time and replication studies are rarer, aside from some remarkable exceptions.
Conclusions: For many of the subgrouping results, we cannot be sure that results generalize, and that subgroup membership will not change from one measurement occasion to the next. In this presentation, recommendations are made for the interpretation and validation of subgrouping results in autism.